#include <iostream>
#include <vector>
using namespace std;

int findPeakElement(vector<int> &nums) {
    int l = 0, r = nums.size() - 1;
    int mid;
    while (l < r) {
        mid = l + (r - l) / 2;
        if (nums[mid] > nums[mid + 1])
            r = mid;
        else
            l = mid + 1;
    }
    return l;
}